The invention relates to an advertising device for advertising designs that change by having a plurality of rotatable prisms which are each preferably triangular, with the surfaces of the prisms being exposed sequentially for view with corresponding surfaces of other prisms in the device to present different advertising displays upon rotation of the prisms and with each prism being illuminated from inside as by a stationary lamp.
Prism advertising devices of this general type are known in the industry. The prism may be disposed horizontally or vertically for display. In large advertising panels taller than approximately 2 meters the prisms are normally disposed vertically, preferably suspended from the upper end, for the sake of mechanical stability. The rectangular panels of each triangular prism are joined together by an equilateral triangular base at each end to stabilize the arrangement. The drive for pivoting the prism generally engages one of these triangular bases, one of which usually has an opening through which the mount and the power supply of an illumination device, such as a fluorescent or neon lamp, extends for mounting the illuminating device within the prism. The lamp remains stationary when the prism is pivoted. The pivoting is intermittent with all of the prisms pivoting simultaneously to present advertising surfaces across the device for viewing in a composite design.
The lamps used in the advertising devices described have a limited, and usually highly variable, service life. Accordingly, lamps fail without predictability. In prior devices, a failed lamp has to be pulled out through one end of the prism, and the new lamp is introduced into the prism in the same way.
The advertising device of the type described can be produced in considerable size, for instance with a height of from 1 meter to 6 meters and a width of from 2 meters to 20 meters. As noted, in relatively large advertising panels the prisms are preferably disposed vertically next to one another. If an advertising device of this kind is designed for operation in the open air, then the prisms and particularly the region above each prism must be carefully protected against the effects of weather in order to protect the mechanical and electrical parts. If a lamp in one prism fails, then the entire prism has to be dismantled so that the lamp can be pulled out of the prism. If the cover on the top of the prism of an advertising wall has to be removed, ladders are needed in order to pull the lamp out at the top or insert a lamp into the prism from the top. Hence the effort and expense for changing a lamp is considerable--and the situation is quite similar even when the prism is horizontally supported.